1. Field of the Invention
The present invention relates to a radio frequency (RF) module, a multi RF module including the RF module, and a method of fabricating the RF module, and more particularly, to an RF module with a multi stack structure which can be manufactured on a wafer, a multi RF module including the RF module, and a method of fabricating the RF module.
2. Description of the Related Art
Radio frequency (RF) refers to frequency used for wireless communication. An RF module processes RF signals, that is, it generates and receives wireless signals. Examples of RF modules are a filter bank constituted of a filter and a phase shifter or the like, a duplexer, a dual duplexer, etc. The filter bank includes a plurality of modulation filters transmitting wireless signals formed by a plurality of RF modules in a predetermined frequency band. Also, the duplexer uses several filters in various ways to properly divide RF signals sent and received through an antenna.
Many wireless communication devices such as cell phones are required to be small and light. However, since RF elements of such communication devices are manufactured separately and then integrated on a substrate, the manufacturing process is complicated and it is difficult to reduce the size of the devices.